<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>

<!--
  布尔类型对象
-->

<script>
    var  bln = true  //  boolean
    var  bln2 = new  Boolean(NaN)   //  Boolean

    console.log(bln2.toString())
    console.log(bln2.valueOf())




</script>
</body>
</html>